In the industrial sector of the production of boxes, using a relatively rigid material, such as for example paper, cardboard, plastic material or other, it is known to cut, from a continuous strip of the pre-chosen material, a flat sheet, the development of which comprises all the walls of the box.
In particular, these so-called “American” boxes, are parallelepiped shaped consisting of six walls, that is, four lateral walls, a lower wall or bottom, and an upper wall or lid. To join together the end edges of the sheet and thus define the internal cavity of the box, the sheet is also provided with a fin, that persons of skill call “K element”; the fin protrudes from a lateral wall and is destined to be glued in correspondence to the edge of an adjacent lateral wall.
Gluing machines are known that glue the fin to the adjacent lateral wall. However, these known gluing machines all have the disadvantage that they require manual alignment and adjustment to the thickness of the pre-cut sheet by the operator, using a reference member that is positioned distant from the gluing unit, so that the gluing of the two parts is not always correct and precise.
Documents US-A-2006/081727 and US-A-2012/129670 describe gluing machines of the known type.
There is therefore a need to perfect a gluing machine to make boxes that can overcome at least one of the disadvantages of the state of the art.
In particular, one purpose of the present invention is to make a gluing machine to make boxes, that is completely automatic, that executes to perfection the gluing of the parts to be glued to each other and that, at the same time, does not require any operation by an operator other than to insert the pre-cut sheet on a support plane of the machine itself.
Another purpose of the present invention is to perfect a method that allows a gluing machine for making boxes to carry out the gluing of the two parts to be glued of the pre-cut sheet in a completely automatic way and in total safety.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.